Jeanine Stifler (aka Stifler's Mom) is the mother of Steve Stifler and Matt Stifler. She is the source of the now wildly famous term "MILF" (Mom I'd Like to F*ck) - first coined by John Cho's character, and one of the only supporting cast members to appear in all four films featuring the original cast. She is a common fantasy among the male students at East Great Falls High. In American Pie, Paul Finch has a "Mrs. Robinson" moment with her (much to the chagrin of Finch's frenemy - Jeanine's son, Steve Stifler) in which he loses his virginity, and subsequently becomes obsessed in the following two films - American Pie 2 and American Wedding - with recreating the moment on a grander scale. The two "come together" for a second rendezvous at the end of American Pie 2 where we see them rocking Jeanine's Mercedes so violently that its alarm is set off. Jennifer Coolidge is set to reprise her role in American Reunion, as is Eddie Kaye Thomas (Finch).

In "American Reunion", she begins dating the widowed Noah Levenstein, after sharing drinks and a joint. She falls in love with Noah because although he is quite geeky, he is a gentleman, interested in her for who she is, instead of a sexual lust like most men. She's also revealed to not be so promiscuous as she appears to be in the first three films. As she truly wants to be loved and treated like a lady, she is fed up with the current man in her life and sees something special in Noah.

In a post-credits scene, she and Noah are on their first date at a movie theater and she performs oral sex on him after being flattered when he romantically wraps his arm around her.